Hearing health and dementia – Authors' reply
Authors: Dongshan Zhu, Shiva Raj Mishra, Salim S Virani, Nipun Shrestha, Fan Jiang
Journal: The Lancet Public Health (2023)

In their Correspondence, Jennifer Deal and Nicholas Reed propose that when estimating the effect of hearing aid use on dementia risk, individuals with hearing loss not using hearing aids should be an alternative reference group. Such grouping based on hearing loss might allow counterfactual assessment of the effect of hearing loss on dementia risk depending on the use (and not use) of hearing aids. In our Article,1Jiang F Mishra SR Shrestha N et al.Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort.Lancet Public Health. 2023; 8: e329-e338Summary Full Text Full Text PDF PubMed Scopus (11) Google Scholar a reference group of people without hearing loss was compared with those with hearing loss who did or did not use hearing aids. Using this reference group (ie, those without hearing loss), the hazard ratio (HR) and 95% CI between the two groups of people with hearing loss who either use or do not use hearing aids can be directly compared. Our results shows that 95% CIs do not overlap between hearing aid users (HR 1·04, 95% CI 0·98–1·10) and non-users (1·42, 1·28–1·57), suggesting that dementia risk among non-users clearly exceeds those who used hearing aids.1Jiang F Mishra SR Shrestha N et al.Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort.Lancet Public Health. 2023; 8: e329-e338Summary Full Text Full Text PDF PubMed Scopus (11) Google Scholar Pádraig Kitterick and Brent Edwards point out that self-reported hearing problems can be distinct from audiometrically-defined hearing loss. The UK Biobank is a community-based prospective cohort study that enrolled participants across the UK between 2006 and 2010 (ie, the baseline period).2Sudlow C Gallacher J Allen N et al.UK biobank: an open access resource for identifying the causes of a wide range of complex diseases of middle and old age.PLoS Med. 2015; 12e1001779Crossref PubMed Scopus (4342) Google Scholar At baseline period, all participants were asked a touchscreen question "Do you have any difficulty with your hearing?" to obtain their self-reported hearing difficulties. Therefore, in our Article,1Jiang F Mishra SR Shrestha N et al.Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohort.Lancet Public Health. 2023; 8: e329-e338Summary Full Text Full Text PDF PubMed Scopus (11) Google Scholar self-reported hearing difficulties (ie, perceived hearing problems) were used consistently to evaluate the association between hearing problems and dementia risk. There might be two kinds of inconsistencies between self-reported hearing problems and audiometrically-defined hearing loss, such as availability of results from a speech-in-noise test. First, those who self-reported having hearing difficulties might have normal audiometrically-defined hearing. In this situation, given that those with self-reported hearing difficulties who did not use hearing aids had a stronger association with dementia than audiometrically defined hearing loss,3Marinelli JP Lohse CM Fussell WL et al.Association between hearing loss and development of dementia using formal behavioural audiometric testing within the Mayo Clinic Study of Aging (MCSA): a prospective population-based study.Lancet Healthy Longev. 2022; 3: e817-e824Summary Full Text Full Text PDF PubMed Scopus (6) Google Scholar the strength of the association in our findings might be overestimated. Second, those who self-reported having normal hearing might have had audiometrically defined hearing loss. These individuals would have been classified into the reference group in our study. Evidence in a subsample of the UK Biobank has shown that speech-in-noise defined hearing loss is linked to an increased risk of dementia.4Stevenson JS Clifton L Kuzma E Littlejohns TJ Speech-in-noise hearing impairment is associated with an increased risk of incident dementia in 82 039 UK Biobank participants.Alzheimers Dement. 2022; 18: 445-456Crossref PubMed Scopus (16) Google Scholar In this scenario, our findings might have underestimated the link between hearing problems and dementia. Hearing impairment (either self-reported or audiometrically defined) has been widely viewed as a modifiable risk factor for dementia, and further studies in causal mechanisms and cost-effectiveness of interventions for dementia prevention are needed.5Livingston G Huntley J Sommerlad A et al.Dementia prevention, intervention, and care: 2020 report of the Lancet Commission.Lancet. 2020; 396: 413-446Summary Full Text Full Text PDF PubMed Scopus (3359) Google Scholar We declare no competing interests. Association between hearing aid use and all-cause and cause-specific dementia: an analysis of the UK Biobank cohortIn people with hearing loss, hearing aid use is associated with a risk of dementia of a similar level to that of people without hearing loss. With the postulation that up to 8% of dementia cases could be prevented with proper hearing loss management, our findings highlight the urgent need to take measures to address hearing loss to improve cognitive decline. Full-Text PDF Open AccessHearing health and dementiaWhether hearing aids delay dementia is a pressing public health question.1 In The Lancet Public Health, Fan Jiang and colleagues2 recently reported that untreated hearing loss is associated with all-cause dementia risk (HR 1·42), with no increased risk among hearing aid users. In their Comment, Gill Livingston and Sergi Costafreda3 raise important considerations for the interpretation of these findings, including that hearing aid users could have greater economic, social, or cognitive resources than non-users. Full-Text PDF Open AccessHearing health and dementiaFan Jiang and colleagues1 recently examined the association between hearing aid use and all-cause and cause-specific dementia in The Lancet Public Health.1 The authors observed that hearing aid use in those who self-report hearing problems appears to modify the risk of dementia. They concluded that the management of hearing loss should be treated as an urgent public health concern to improve health outcomes in later life. Full-Text PDF Open Access